Work vehicle

ABSTRACT

A work vehicle includes an automatic steering switching tool to start or end automatic steering of a vehicle body and a setting operation tool to select a setting for the automatic steering of the vehicle body. The automatic steering switching tool and the setting operation tool are positioned at an upper portion of a steering tower and below a steering wheel.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a work vehicle capable of automatically steering a vehicle body so that the vehicle body travels on a target travel path.

2. Description of the Related Art

A known example of work vehicles is disclosed in Japanese Unexamined Patent Application Publication, Tokukai, No. 2016-23973. The work vehicle disclosed in Japanese Unexamined Patent Application Publication, Tokukai, No. 2016-23973 is capable of automatically steering the travel vehicle body so that the travel vehicle body travels on a target travel path. The work vehicle disclosed in Japanese Unexamined Patent Application Publication, Tokukai, No. 2016-23973 includes a setting operation tool for selecting a setting for automatic steering of the travel vehicle body (for example, the “setting buttons 101” in the document). The work vehicle disclosed in Japanese Unexamined Patent Application Publication, Tokukai, No. 2016-23973 includes, as the setting operation tool, a touch screen configured to be displayed on a monitor (39) positioned forward of the steering wheel (namely, the “steering wheel (20)” in the document).

SUMMARY OF THE INVENTION

The work vehicle disclosed in Japanese Unexamined Patent Application Publication, Tokukai, No. 2016-23973 is structured such that the driver needs to reach out forward beyond the steering wheel to operate the setting operation tool. The setting operation tool thus cannot be operated easily.

The above circumstances have led to a demand for a work vehicle including an easily operable operation tool for automatic steering.

A preferred embodiment of the present invention includes a steering wheel to steer a vehicle body of the work vehicle, a steering tower for which the steering wheel is provided, an automatic steering mechanism to automatically steer the vehicle body so that the vehicle body travels on a target travel path, an automatic steering switching tool to start or end automatic steering of the vehicle body, and a setting operation tool to select a setting for the automatic steering of the vehicle body, wherein the automatic steering switching tool and the setting operation tool are at an upper portion of the steering tower and below the steering wheel.

The above structural arrangement has an automatic steering switching tool and a setting operation tool positioned under and close to the steering wheel. This allows the driver to reach the automatic steering switching tool and the setting operation tool without reaching out over a large distance. The automatic steering switching tool and the setting operation tool are thus easily operable.

A preferred embodiment of the present invention may preferably have a structural arrangement such that the setting operation tool is on a side of a rotation axis of the steering wheel on which side a driver's seat is present.

The above structural arrangement enables the setting operation tool to be close to the driver. This allows the driver to reach the setting operation tool easily.

A preferred embodiment of the present invention may preferably be structurally arranged such that the setting operation tool includes a plurality of operation switches, and the plurality of operation switches are arranged laterally.

With the above structural arrangement, the respective distances between the driver and all of the plurality of operation switches are equal or substantially equal to one another. This allows the driver to reach each of all the plurality of operation switches easily.

A preferred embodiment of the present invention may preferably further include a forward-reverse switching tool to switch a travel direction of the vehicle body between a forward travel and a reverse travel, wherein the automatic steering switching tool and the forward-reverse switching tool are on one side of the rotation axis of the steering wheel in a left-right direction of the vehicle body.

With the above structural arrangement, the automatic steering switching tool and the forward-reverse switching tool are both on one side of the rotation axis of the steering wheel in the left-right direction of the vehicle body. This eliminates the need for the driver to use both hands. That is, this structure allows the driver to use only one hand, and thus allows each of the automatic steering switching tool and the forward-reverse switching tool to be operated easily.

A preferred embodiment of the present invention may preferably be structurally arranged such that the automatic steering switching tool and the forward-reverse switching tool are at respective positions different from each other in a front-back direction of the vehicle body.

With the above structural arrangement, the respective distances between (i) the driver and (ii) the automatic steering switching tool and the forward-reverse switching tool differ from each other. This prevents the driver from confusing the automatic steering switching tool and the forward-reverse switching tool with each other even if the automatic steering switching tool and the forward-reverse switching tool are both present on one side of the rotation axis of the steering wheel in the left-right direction of the vehicle body.

A preferred embodiment of the present invention may preferably further include a display to display information on the automatic steering of the vehicle body, wherein the display is forward of the steering wheel.

The above structural arrangement allows the driver to see the display without looking away from the front.

The above and other elements, features, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a left side view of a tractor.

FIG. 2 is a plan view of a tractor.

FIG. 3 is a rear view of a front panel.

FIG. 4 is a plan view of a front panel.

FIG. 5 is a rear view of the internal structure of a steering tower.

FIG. 6 is a rear view of the internal structure of a front panel.

FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 1 .

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention will be described below with reference to drawings.

FIGS. 1 and 2 each illustrate a tractor (work vehicle). The tractor includes a travel vehicle body 1. The travel vehicle body 1 is, for example, of a four-wheel drive type. The travel vehicle body 1 is provided with a pair of left and right drivable and steerable front wheels 2F and a pair of left and right drivable rear wheels 2B. The travel vehicle body 1 is also provided with a pair of left and right fenders 3 that cover the pair of left and right rear wheels 2B, respectively.

The travel vehicle body 1 has a front half provided with a motor section 4. The motor section 4 includes an engine E and a hood 5 that covers the engine E. The travel vehicle body 1 has a rear half provided with a driver section 6 for a driver to get in. The driver section 6 includes a driver's seat 7 for a driver to sit on and a front panel 8 in front of the driver's seat 7. The travel vehicle body 1 is provided with a ROPS 9 near the driver's seat 7. The travel vehicle body 1 has a rear end provided with a link mechanism 10 to which a work device (not shown in the drawings) such as a rotary tiller device is attachable.

The tractor is provided with a GPS antenna unit 11 and an inertia measuring device (not shown in the drawings). The GPS antenna unit 11 is configured to receive positional information from GPS (global positioning system) satellites and determine the position of the travel vehicle body 1 on the basis of the positional information received. The GPS antenna unit 11 is supported by an upper portion of the ROPS 9 at such a position as to have a left-right center that coincides with the left-right center of the vehicle body. The inertia measuring device is configured to measure inertia information (such as information on a yaw angle, a pitch angle, and a roll angle) of the travel vehicle body 1. The tractor includes an automatic steering mechanism 12 (see FIGS. 5 to 7 ) configured to, on the basis of (i) the position of the travel vehicle body 1 as determined by the GPS antenna unit 11 and (ii) the inertia information of the travel vehicle body 1 as measured by the inertia measuring device, automatically steer the travel vehicle body 1 so that the travel vehicle body 1 travels on a target travel path.

As illustrated in FIGS. 3 to 6 , the front panel 8 includes a meter panel 13, a monitor 14 (display device), and a steering tower 15. The steering tower 15 is provided with, for example, a steering wheel 16. The meter panel 13 is positioned under a front portion of the steering wheel 16. The meter panel 13 is provided with, for example, a fuel meter, an engine tachometer, a water temperature meter, a liquid crystal display section, and various lamps. The monitor 14 is positioned above the meter panel 13 and in front of the steering wheel 16. The monitor 14 is configured to display information on automatic steering of the travel vehicle body 1. The monitor 14 functions as a guidance monitor for automatic steering of the travel vehicle body 1.

The steering tower 15 is positioned in front of the driver's seat 7. The steering tower 15 is provided with a steering wheel 16, a steering shaft 17, a steering post 18, an automatic steering switching lever 19, a forward-reverse switching lever 20, setting switches 21, a switch 22, and an automatic steering mechanism 12. Members such as the steering post 18 and the automatic steering mechanism 12 are covered by a steering cover 23.

The steering tower 15 is supported by a support frame 29 via the steering post 18 in such a manner as to be swingable about a swing axis X1 extending in the left-right direction of the vehicle body. The tractor is provided with a tilt mechanism 24 configured to adjust the position of the steering tower 15 about the swing axis X1. The front panel 8 has a lower portion provided with a tilt pedal 25 with which to operate the tilt mechanism 24. Pressing the tilt pedal 25 with a foot allows the position of the steering tower 15 to be adjusted with use of the tilt mechanism 24. Releasing the pressed tilt pedal 25 causes the position of the steering tower 15 to be fixed.

The steering wheel 16 is for use to steer the travel vehicle body 1. The steering shaft 17 is connected with the steering wheel 16 and extends downward from the steering wheel 16. The steering shaft 17 is supported by the steering post 18 in such a manner as to be rotatable about the axis of the steering shaft 17 (that is, the rotation axis of the steering wheel 16) Z1 with use of the steering wheel 16. The steering post 18 includes (i) an upper insertion portion 26 through which an upper portion of the steering shaft 17 is present and by which the upper portion is supported, (ii) a lower insertion portion 27 through which a lower portion of the steering shaft 17 is present and by which the lower portion is supported, and (iii) a base portion 28 supporting the lower insertion portion 27. The base portion 28 is supported by the support frame 29 in such a manner as to be swingable about the swing axis X1.

The automatic steering switching lever 19 is for use to start or end automatic steering of the travel vehicle body 1 and otherwise. The forward-reverse switching lever 20 is for use to switch the travel direction of the travel vehicle body 1 between a forward travel and a reverse travel. The automatic steering switching lever 19 and the forward-reverse switching lever 20 are positioned at an upper portion of the steering tower 15 and below the steering wheel 16. The automatic steering switching lever 19 and the forward-reverse switching lever 20 are both positioned on one side of the rotation axis Z1 of the steering wheel 16 in the left-right direction of the vehicle body (for the present preferred embodiment, on the left side). The automatic steering switching lever 19 and the forward-reverse switching lever 20 are present at respective positions different from each other in the front-back direction of the vehicle body. For the present preferred embodiment, the automatic steering switching lever 19 is positioned forward of the forward-reverse switching lever 20.

The steering tower 15 is provided with a forward-reverse switch 30 configured to switch the travel direction of the travel vehicle body 1 between a forward travel and a reverse travel in accordance with the operation position of the forward-reverse switching lever 20. The forward-reverse switch 30 is capable of detecting the operation position of the forward-reverse switching lever 20. The forward-reverse switch 30 is positioned under that portion of a gear case 31 which is present on the left side from the rotation axis Z1 of the steering wheel 16. The forward-reverse switch 30 is supported by the steering post 18 via a stay 32.

The forward-reverse switching lever 20 is switchable to any of (i) a forward-travel position for the travel vehicle body 1 to travel forward, (ii) a reverse-travel position for the travel vehicle body 1 to travel backward, and (iii) a neutral position for the travel vehicle body 1 to stop. The forward-reverse switching lever 20 extends upward from a height below the gear case 31 to a height between the upper end and the lower end of the steering wheel 16. The forward-reverse switching lever 20 includes (i) a grip portion 20 a for the driver to hold, (ii) a connection portion 20 b connected with the forward-reverse switch 30, and (iii) a rod portion 20 c extending between the grip portion 20 a and the connection portion 20 b. The grip portion 20 a is positioned at a height between the upper end and the lower end of the steering wheel 16. The rod portion 20 c extends upward from the connection portion 20 b in such a pattern as to be spaced apart from the gear case 31.

The setting switches 21 are each for use to select a setting for automatic steering of the travel vehicle body 1. The setting switches 21 include a correction switch 33, a dial switch 34, and a switch 35. The correction switch 33, the dial switch 34, and the switch 35 are positioned at an upper portion of the steering tower 15 and below the steering wheel 16. The correction switch 33, the dial switch 34, and the switch 35 are positioned on that side of the rotation axis Z1 of the steering wheel 16 on which the driver's seat 7 is present (that is, on the back side). The correction switch 33, the dial switch 34, and the switch 35 are arranged laterally in this order from the left side.

The tractor is configured to determine the position of the travel vehicle body 1 on the basis of (i) the position of the travel vehicle body 1 as determined by the GPS antenna unit 11 and (ii) the inertia information of the travel vehicle body 1 as measured by the inertia measuring device. The correction switch 33 is for use to correct the determined position of the travel vehicle body 1. The correction switch 33 includes (i) a left correction switch portion 33 a to correct the determined position of the travel vehicle body 1 to the left side and (ii) a right correction switch portion 33 b to correct the determined position of the travel vehicle body 1 to the right side.

The dial switch 34 is capable of being pressed and rotated. Pressing the dial switch 34 causes, for example, any of various instructions to be entered. Long-pressing the dial switch 34 causes, for example, any of various menus to be invoked. Rotating the dial switch 34 clockwise or counterclockwise causes, for example, any of various items to be selected. The functions corresponding to the different operations of the dial switch 34 are, however, not limited to the above (that is, the entry, menu invocation, and selection).

The switch 35 is capable of being pressed. Pressing the switch 35 causes, for example, the previous screen to be displayed. Long-pressing the switch 35 causes, for example, the home screen to be displayed. The functions corresponding to the different operations of the switch 35 are, however, not limited to the above (that is, displaying the previous screen or home screen). The switch 22 is for use to operate the headlights and turn signals. The switch 22 is positioned to the right side of the rotation axis Z1 of the steering wheel 16.

As illustrated in FIGS. 5 to 7 , the automatic steering mechanism 12 includes (i) a motor M configured to drive the steering shaft 17 to rotate, (ii) a gear mechanism G configured to transmit the driving force of the motor M to the steering shaft 17, and (iii) a gear case 31 containing the gear mechanism G. The motor M and the gear case 31 are arranged vertically. Specifically, the motor M is positioned above the gear case 31.

The gear mechanism G includes (i) an output gear 36 provided for the output shaft of the motor M, (ii) a first relay gear 37 meshing with the output gear 36, (iii) a second relay gear 38 coaxial with the first relay gear 37 and configured to rotate together with the first relay gear 37, and (iv) an input gear 39 provided on the steering shaft 17 and meshing with the second relay gear 38. The gear case 31 is positioned under the steering wheel 16 and is present at such a position as to be shifted to the left side with respect to the rotation axis Z1 of the steering wheel 16. The gear case 31 has a thickness T1 in the up-down direction which thickness T1 is equal to or substantially equal to the thickness T2 of the motor M in the up-down direction. The gear case 31 is divided into two vertically arranged halves, namely an upper case portion 31 a and a lower case portion 31 b. The gear case 31 is supported by the steering post 18 with the steering shaft 17 extending through the gear case 31 in the up-down direction. The upper case portion 31 a has an upper surface portion to which a lower end portion of the upper insertion portion 26 is fixed (bolted). The lower case portion 31 b has a lower surface portion to which an upper end portion of the lower insertion portion 27 is fixed (bolted).

The motor M is positioned under the steering wheel 16 and to the left of the steering shaft 17. The motor M is supported by the gear case 31. Specifically, the motor M is supported by (that is, placed on and supported by) a portion of the gear case 31 which portion is positioned to the left side of the rotation axis Z1 of the steering wheel 16. The motor M is fixed (screwed) to the upper surface portion of the upper case portion 31 a.

For the preferred embodiments described above, the motor M is positioned under the steering wheel 16 and to the left of the steering shaft 17. The motor M may alternatively be positioned under the steering wheel 16 and to the right of the steering shaft 17.

For the preferred embodiments described above, the motor M is positioned above the gear case 31. The gear case 31 may alternatively be positioned above the motor M. The motor M and the gear case 31 may alternatively be arranged in the left-right direction. The motor M and the gear case 31 may alternatively be arranged in the front-back direction.

For the preferred embodiments described above, the motor M is supported by a portion of the gear case 31 which portion is positioned to the left side of the rotation axis Z1 of the steering wheel 16. The motor M may alternatively be supported by a portion of the gear case 31 which portion is positioned to the right side of the rotation axis Z1 of the steering wheel 16. The motor M may alternatively be supported by a member other than the gear case 31.

For the preferred embodiments described above, the gear case 31 is positioned under the steering wheel 16 and is present at such a position as to be shifted to the left side with respect to the rotation axis Z1 of the steering wheel 16. The gear case 31 may alternatively be positioned under the steering wheel 16 and is present at such a position as to be shifted to the right side with respect to the rotation axis Z1 of the steering wheel 16.

For the preferred embodiments described above, the gear case 31 has a thickness T1 in the up-down direction which thickness T1 is equal to or substantially equal to the thickness T2 of the motor M in the up-down direction. The gear case 31, however, does not necessarily have a thickness T1 in the up-down direction which thickness T1 is equal to or substantially equal to the thickness T2 of the motor M in the up-down direction. The gear case 31 may alternatively have a thickness T1 in the up-down direction which thickness T1 is, for example, larger than the thickness T2 of the motor M in the up-down direction.

For the preferred embodiments described above, the forward-reverse switching lever 20 extends upward from a height below the gear case 31 to a height between the upper end and the lower end of the steering wheel 16. The arrangement of the forward-reverse switching lever 20 is, however, not limited to that described for the preferred embodiments described above. The forward-reverse switching lever 20 may, for instance, have an upper end portion (that is, the grip portion 20 a) positioned below the lower end of the steering wheel 16.

For the preferred embodiments described above, the setting switches 21 include a correction switch 33, a dial switch 34, and a switch 35. The arrangement of the setting switches 21 is, however, not limited to that described for the preferred embodiments described above. The setting switches 21 may, for instance, alternatively include not only the correction switch 33, the dial switch 34, and the switch 35, but also a switch(es) other than the correction switch 33, the dial switch 34, and the switch 35. The setting switches 21 may alternatively include a switch(es) other than the correction switch 33, the dial switch 34, and the switch 35 in place of at least one of the correction switch 33, the dial switch 34, and the switch 35. Further alternatively, the steering tower 15 may include only one operation switch as a setting switch 21.

For the preferred embodiments described above, the setting switches 21 are positioned on that side of the rotation axis Z1 of the steering wheel 16 on which the driver's seat 7 is present (that is, on the back side). The setting switches 21 may alternatively be positioned on one side of the rotation axis Z1 of the steering wheel 16 in the left-right direction of the vehicle body.

For the preferred embodiments described above, the correction switch 33, the dial switch 34, and the switch 35 are arranged laterally. The correction switch 33, the dial switch 34, and the switch 35 may alternatively be arranged in the front-back direction.

For the preferred embodiments described above, the automatic steering switching lever 19 and the forward-reverse switching lever 20 are both positioned on the left side of the rotation axis Z1 of the steering wheel 16. The automatic steering switching lever 19 and the forward-reverse switching lever 20 may alternatively be both positioned on the right side of the rotation axis Z1 of the steering wheel 16. The automatic steering switching lever 19 and the forward-reverse switching lever 20 may alternatively be positioned such that one of the two levers is present on one side of the rotation axis Z1 of the steering wheel 16 in the left-right direction of the vehicle body and that the other of the two levers is present on the other side of the rotation axis Z1 of the steering wheel 16 (separate positioning).

For the preferred embodiments described above, the automatic steering switching lever 19 is positioned forward of the forward-reverse switching lever 20. The forward-reverse switching lever 20 may alternatively be positioned forward of the automatic steering switching lever 19. The automatic steering switching lever 19 and the forward-reverse switching lever 20 may alternatively be present at the same position in the front-back direction of the vehicle body.

For the preferred embodiments described above, the forward-reverse switch 30 is positioned under that portion of the gear case 31 which is present on the left side from the rotation axis Z1 of the steering wheel 16. The position of the forward-reverse switch 30 is, however, not limited to the above position for the preferred embodiments described above. The forward-reverse switch 30 may be positioned, for example, under that portion of the gear case 31 which is present on the right side from the rotation axis Z1 of the steering wheel 16. The forward-reverse switch 30 may alternatively be present at a position that is not under the gear case 31.

For the preferred embodiments described above, the automatic steering switching tool is in the form of an automatic steering switching lever 19. The automatic steering switching tool may alternatively be a switch.

For the preferred embodiments described above, the forward-reverse switching tool is in the form of a forward-reverse switching lever 20. The forward-reverse switching tool may alternatively be a switch.

For the preferred embodiments described above, the setting operation tool is in the form of setting switches 21. The setting operation tool may alternatively be a lever.

For the preferred embodiments described above, the tractor is provided with a tilt mechanism 24. The tractor is, however, not necessarily provided with a tilt mechanism 24.

For the preferred embodiments described above, the tractor is not provided with a cabin covering the driver section 6. The tractor may, however, be provided with such a cabin in place of the ROPS 9.

Preferred embodiments of the present invention are applicable to work vehicles (for example, tractors) capable of automatically steering the travel vehicle body so that the travel vehicle body travels on a target travel path.

While preferred embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims. 

The invention claimed is:
 1. A work vehicle, comprising: a steering wheel to steer a vehicle body of the work vehicle; a steering tower for which the steering wheel is provided; an automatic steering switching lever to start or end automatic steering of the vehicle body; and a setting switch to select a setting for the automatic steering of the vehicle body; wherein the automatic steering switching lever and the setting switch are at an upper portion of the steering tower and below the steering wheel.
 2. The work vehicle according to claim 1, wherein the setting switch is on a side of a rotation axis of the steering wheel on which side a driver's seat is present.
 3. The work vehicle according to claim 1, wherein the setting switch includes a plurality of operation switches arranged laterally.
 4. The work vehicle according to claim 1, further comprising: a forward-reverse switching lever to switch a travel direction of the vehicle body between a forward travel and a reverse travel; wherein the automatic steering switching lever and the forward-reverse switching lever are on one side of the rotation axis of the steering wheel in a left-right direction of the vehicle body.
 5. The work vehicle according to claim 4, wherein the automatic steering switching lever and the forward-reverse switching lever are present at respective positions different from each other in a front-back direction of the vehicle body.
 6. The work vehicle according to claim 1, further comprising: a display to display information on the automatic steering of the vehicle body; wherein the display is forward of the steering wheel. 